A person undergoing surgical procedures advantageously is maintained at a selected temperature by application of external means to prevent body the temperature from dropping below a desired level. Patient heating devices are desirable during surgical procedures as the surgical environment is normally maintained at a relatively cool temperature to aide in the comfort and efficient execution of the surgical procedure by the surgical personnel. Various suggestions have been provided in connection with maintaining the body temperature at a desired warmer level including immersion in a warm bath and alternatively application of body heating elements to the patient""s body. U.S. Pat. No. 5,292,347 which issued Mar. 8, 1994 discloses various elements to be applied to the patient""s body to supply a heated vapor to the body that lies within an enclosure applied to a particular portion of the patient""s body. The system discloses a total body enclosure member and, as an alternative, a cap applied to the top of the patient""s head. A non-porous enclosure preferably formed of a thermally insulated material is used so that the heat inside of the closure will not escape. The insulated cover is formed with a condensation accumulating system, and the head unit includes an absorbent material to soak up the condensation. The head structure of the enclosure is also provided with vents to allow excess air and vapor to escape. The system provides a controlled saturated vapor and requires the special body members to appropriately provide the supply of the vapor to the body.
An alternative but similar system is shown in U.S. Pat. No. 4,572,188 which discloses a system including a full body enclosure or a head enclosure with an encircling air band through which air is supplied to surround the head and particularly from the forehead and above. The enclosure pass through a plurality of different passageways and exiting into the body enclosed portion. The structure of U.S. Pat. No. 4,572,188 requires a special air tube which is inflated for sealed engagement with the head in combination with the outer head chamber and extended therefrom. The air is forced within the head band and exits through an outer single port. The tube is specially formed to form insulation and support the head of the patient as well as providing an air passage between the lower portion of the patient""s head and the end portion 64. A somewhat similar but cooling device is shown in U.S. Pat. No. 3,908,655 where the patient""s head is located within a chamber and an air conditioning applied to provide a cooling of the head directly.
The heating of the patient is preferably through the head portion as a result of the rather great amount of blood which flows through the human head, which when heated will then travel throughout the patient""s body at a standard temperature providing an improved heat transfer and distribution. As a result the body is maintained at a comfortable desired temperature throughout the surgical procedure while maintaining a comfortable temperature for medical personnel. This permits optimal efficiency by the surgical personnel. Generally, the patient""s temperature will be monitored by skilled personnel during a surgical procedure.
Although the prior art thus recognizes the necessity in various cases to apply air, either thermal or cooling air, to the body to control the temperature during surgical procedures, there remains a need for a very simple and inexpensive single use enclosure unit which can be applied to maintain and control the body temperature during such surgical procedures and thrown away.
In summary, devices have been proposed to enclose the entire head of the person and others to enclose the upper head portion. Separate individual systems have been suggested, but a single relatively simple and inexpensive unit which can be applied in various applications has not been suggested.
The present invention provides a simple and relatively inexpensive flexible enclosure which provides for a single use, throw away usage.
Generally, in accordance with the present invention, a bag unit is provided with an open end in combination with a head enclosure including the open end and an outer air supply chamber. The air supply may be any suitable source of temperature controlled air, and for surgical procedure a supply of heated air. The enclosure bag may be secured with the bag opening secured by various closure elements about the neck portion immediately below the head of the patient, at some further body portion or alternatively above the neck and about a face portion such as beneath the ears and over the nose of the patient to apply the heating effect to the top portion of the head. In each case the bag is preferably formed with appropriate openings for interconnection of appropriate tubing such as for breathing, cleansing and so forth.
In the preferred embodiment, the bag is a simple, biocompatible plastic clear bag which includes an internal separating wall which extends over the top of the head and preferably to one side thereof and defines the air supply chamber to the outer side of the wall and to the other side a head enclosure chamber. The flexible plastic bag is preferably a clear plastic, or at least the frontal part includes a clear portion to allow visual monitoring of the patient. The outer bag wall includes a releasable connection for an air supply tube to receive the heated air. The air is distributed from the supply chamber into the head chamber via the separating wall which is provided with appropriate openings to distribute the air in an optimum manner over and around the head of the patient. The openings may be defined with air directing flaps, and in addition internal walls within the head chamber may be provided to improve the air distribution in accordance with any particular desired configuration.
The bag to be applied to the upper end of the head may be constructed as a smaller unit with a lesser length and have the open end particularly adapted to fitting about the head beneath the ears and over nose portion, or other desired head portions, for firm attachment of the thin flexible cap to the patient""s head. The smaller head unit is preferably also provided with appropriate internal separation to produce an air inlet chamber and a head chamber coupled to the face portion to distribute the air in an optimal manner.
The present invention thus provides a very simple and readily constructed flexible bag which can be produced at a relatively low cost and permits the single time usage of the device to maintain the desired maximum sanitary condition required in operating equipment and particularly the equipment used during a surgical procedure.